Chuck.



H. L. mvisou & E. 1). YORTY.

I CHUCK. APPLICATION FILED APR-13,1906.

928, 1 1 1. 1 Patented July 13, 1909.

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UNITED STATES PATENT oEEIoE.

HENRY L. DAVISON AND EDWIN D. YORlY, OF LINCOLN, NEBRASKA.

CHUCK.

Patented July 13, 1909.

Application filed April 13, 1906. Serial No. 311,491.

To all whom it may concern:

Be it known that we, HENRY L. DAVISON and EDWIN D. YORTY, citizens of the United States, residing at Lincoln, in the county of Lancaster and State of Nebraska, have invented certain new and useful Improvements in Chucks, of which the following is a specification.

Our invention relates to chucks for holding small tools and its object is to provide a simple, strong and durable device for the purpose stated, thus reducing the cost to manufacture, and rendering the appliance less liable to get out of order.

A further object of our invention is to provide a quick-acting mechanism both for securing the operating tool in place and also for releasing the same.

Another object of our improved chuck is to produce a device of the character described that will retain the operating tool securely in position and in which the holding power will be automatically increased in direct ratio to the pressure which is applied longitudinally to the working tool.

l/Ve accomplish these and other minor results by the mechanism hereinafter described and clearly shown in the accom panying drawing which forms a part of this specification and in which Figure 1 is a longitudinal sectional view of a lathe chuck embodying our improvements; Fig. 2 is a front elevation of the same; Fig. 3 is a similar view with the cap removed to disclose some of the interior mechanism; Fig. 4 is a perspective View of the guide plate and posts, and Fig. 5 is a perspective view of one of the operating cams.

Referring to the drawing the numeral 6 indicates the body or shell of the chuck which is in the form of a hollow cylinder, and formed integral therewith is a rearwardly projecting cylindrical shaft 7 Encircling its forward margin is an outwardly projecting rim 8 and a cap 9 is removably secured to the front of the shell by adjusting screws 10 which engage the rim 8. Duplicate jaws 11 provided with teeth 12 longitudinally co-extensive with the jaws, are placed diametrically opposite each other within the shell their forward ends projecting through a slot 12 in the cap 9, and their rear portions engaging a slot 18 in a guide plate 14: rigidly secured to the cap 9 by posts 15, having threads at the outer ends which are provided with nuts 16 between which the cap is clamped. To the rear end of one of said jaws is secured a dowel pin 17 which has a sliding fit in a mortise 18 in the companion jaw. A spring 19 engaging holes 20 in the jaws tends to keep them apart.

Duplicate cams 21, in ring form, are secured to the inner face of the shell 6 by screws 22, and are spaced apart to correspond with lugs 23 projecting from the outer edges of the jaws l1. Said lugs are held in engagement with the side of said cams by a circular disk 24, having a guide pin 25 projecting rearwardly from its center and having a sliding engagement with a longitudinal bore 26 formed in the shank 7, the said disk being held in an extended position against the ends of the jaws 11 by a spring 27, thus tending to hold the lugs 23 in yielding contact with the rear faces of the cam rings 21. The centers of the cap 9 and the guide plate 14. are provided with central openings 28, approximating in diameter the maximum distance between the jaws to admit the shank of a tool when in engagement with the jaws.

To operate the jaws the periphery of the cap 9 is grasped by the hand and rotated on the shell 6. Since the guide plate 1 1 is secured to the cap, the two will move in unison and as the jaws 11 are in engagement with slots 12and 13 the said jaws will be carried with the cap when the latter is rotated as before stated. The outer margins 29 of the jaws are curved transversely to correspond with the radius of curvature of the inner faces 30 of the cams 21, and when the cap 9 is rotated the margins 29 will engage the 1 faces 30 and as the movement is continued the wedge action will force the jaws radially toward the center, the inner margins of the jaws being kept parallel by the combined action of the duplicate cams 21. The eccentricity of the cam faces 30 is so related to the shell perimeter that the hand will afford suflicient power to cause the jaws to grasp the tool inserted between them with considerable firmness, no wrench being required, and by a reverse movement of the cap the jaws will readily and easily be made to release the tool. Although this procedure will secure the tool it is not designed to depend upon this action alone of the cams to fix the tool while work is being done; an auxiliary movement being brought into action automatically as soon as the tool begins to cut.

As the tool presses against the material upon which it acts there is an end thrust upon the jaws which are yieldingly held by the disk 24: as hereinbefore stated. The outer margins 29 of the jaws are inclined longitudinally, as indicated by the numeral 31, and these sloping edges engaging the inner faces 30 of the cams 21, act as powerful wedges to drive the jaws centrally and thus greatly increase their holding power. As soon as the end thrust is removed, the spring 27 will restore the jaws to their primary holding position, with the lugs 23 bearing against the posterior surfaces of the ring cams 21. To release the tool entirely from the grasp of the jaws, the cap must be turned in a reverse direction when the jaws will be immediately released fromtheir forced engagement with the cam surfaces 30.

It will be noted that the aws and easing move relatively, both axially and circumferentially, of the casing.

Having thus described our invention what we claim as new and desire to secure by Letters Patent, is as follows 1. A device for the purpose specified, including a shell having a shank, a slotted rotatable cap for the shell, a slotted guide-plate located in the shell and rigidly attached to said cap, jaws mounted to slide longitudinally in said guide-plate and cap and provided with inclines on their outer margins extending in a general direction parallel with the axis of the device, means cooperating with said jaws when slid for radially adjusting same, said means comprising rings surrounding said jaws and having cam faces engaging said inclines.

2. A device for the purpose specified, including a shell, a cap rotatably mounted on said shell, a guide-plate located in the said shell and rigidly attached to the said cap, movable jaws engaging slots in the said cap and guide plates, and having inclined edges, cams secured to the inner face of the said shell and adapted to engage the edges of said jaws, and yielding means normally holding said jaws in an extended position.

3. A device for the purpose specified, including a shell having a shank, a slotted cap rotatably adjustable on the shell, a slotted guide-plate located in the said shell and rigidly attached to said cap, movable jaws engaging said slots in the cap and guide plate, yielding means for normally holding the jaws in an extended position radially, and means for contracting said jaws radially against the action of said yielding means.

4:. A device for the purpose specified, including a shell, a slotted cap rotatably mounted upon said shell, a slotted guideplate rigidly attached to said cap, movable jaws engaging the slots in the cap and guide plate, and having inclined outer ed es, a spring tending to separate the aws, a spiral spring tending to extend the aws longitudinally, and rings surrounding the jaws and having cam faces engaging the jaws.

5. A chuck comprising a casing, a ring connected thereto having eccentric inner faces, jaws mounted within the ring and having a longitudinal wedging engagement therewith, said aws and casing being movable relatively, both axially and circumferentially, of the casing.

In testimony whereof we affix our signatures in presence of two witnesses.

HENRY L. DAVISON. EDWVIN D. YORTY.

itnesses Louis HAGEMANN, J. B. Hansen. 

